[frankmcsherry]

I'm not at OSDI or I would have asked there, but:

1. Your skepticism for using Rust cites [26], the PLOS paper from the same people who did [27]. They've essentially recanted, in that their PLOS talk was right after Niko's keynote, and he then talked them through how interior mutability works in Rust. Other than [26], are there other lingering concerns? I could imagine so, but it would be great to take stock.

2. You don't seem to page to disk, and do OOM shootdowns instead. If you did enable disk paging, how comically bad an idea does a tracing GC become? :D Naively, I could imagine RC-GC being less horrible, but perhaps that's my built-in (and absolutely for real) bias.

[DblPlusUngood]

1. I wouldn't say we are skeptical of Rust, I'm sure it could be made to work well and we would love to see such a Rust kernel! I do wonder whether it would be harder to implement highly-concurrent data structures in Rust though, such as the directory cache.

2. GC performance would be basically unaffected by paging, since kernels don't page their own heaps out to disk and thus a kernel heap access would never have to wait for a disk IO. Or maybe you had something else in mind?

[frankmcsherry]

1. Jon sits two desks away, right? ;)

Re 2., I assumed (incorrectly, it seems) that virtual memory mappings can eventually spill to disk. If you grab 1/32 of RAM For the kernel, then you could only virtually map 16x RAM if the page tables have 512 entries. Admittedly, I took my OS class in the previous millennium, so I might be out of date here...